Although extensive research has been conducted on the regenerants for unmodified and SBS-modified asphalt, in-depth studies on the activation of regenerants to restore the SBS cross-linked network while preserving their diffusion performance have not yet been reported. This study quantitatively evaluated the activation effect of self-healing regenerants on SBS cross-linked networks by testing the activation degree of 6%, 8%, and 10% cross-linked networks with self-healing regenerants; the phase structure of SBS-modified asphalt before and after regeneration was examined using fluorescence microscopy (FM); the underlying mechanism of the reactive regenerant was elucidated by Fourier Transform Infrared Spectroscopy (FTIR) and Gel Permeation Chromatography (GPC); furthermore, the rheological response characteristics of the reactive regenerant and conventional regenerant were comparatively analyzed. The findings indicated that the SBS cross-linked network self-healing regenerant exhibited a more pronounced activation effect on aged asphalt. Specifically, when the dosage of the regenerant reaches 8%, its repairing effect on the cross-linked network becomes particularly significant. Reconstructing the cross-linked network structure of SBS-modified asphalt enabled the recovery of the viscoelastic properties of the recycled asphalt. Nevertheless, an excessive dosage of the regenerant failed to further enhance the cross-linked structure in a meaningful way and might even exert an adverse impact on the high-temperature performance of the recycled asphalt.